1. Field of the Invention
The present invention relates to surgical instruments for performing laparoscopic and endoscopic surgical procedures, and more particularly to devices for securing instruments such as cannulas in an incision in a patient's body during the surgical procedure.
2. Discussion of the Prior Art
In recent years, laparoscopic and endoscopic surgical procedures have become increasingly popular for performing major surgical operations In such a procedure, a small incision or puncture is made in the patient's body to provide access for a tube or a cannula device which is inserted into the patient's body to allow for viewing the surgical site and for the insertion of instruments used in performing the surgical procedure. Typically, a trocar device is used to penetrate the body wall, whereby a sharpened point or tip of the trocar assembly creates the path to the surgical site. A cannula is provided as part of the trocar assembly, so that when the pointed piercing mechanism is removed, the cannula remains in place to maintain access to the surgical site. Several incisions may be made to provide numerous access ports to the surgical objective, and once the cannulas are in place, various surgical instruments such as scissors, dissectors, retractors or the like, may be inserted by a surgeon to perform the surgery. Typically, a scope device is used to view the area directly, or a miniature camera is used to display the surgical site on a video monitor set up in the operating room.
The primary benefit of such minimally invasive surgical techniques is the reduction of scarring and consequently, minimizing damage to surrounding tissue and organs. As a consequence, recovery time is greatly reduced for the patient.
During a laparoscopic surgical procedure, gas is introduced into the body cavity by means of a pneumoperitoneum needle to inflate the cavity to provide greater access to the surgical area and minimize obstruction during surgery. The trocar assembly is then inserted into the body cavity, usually the abdomen, to a point adjacent the tissue or organ which is the surgical objective. After the pointed obturator is removed, the cannula remains in place in the patient's body. Due to the insufflation of the gas, it is necessary to maintain a gas seal at each of the cannulas in position in the body. It is also necessary to maintain the cannulas in a relatively immobile state, primarily to free the surgeon and the surgical assistants from having to hold the cannulas to prevent these instruments from backing off and consequently falling out of the incision. Furthermore, movement of the cannulas may result in a breakdown of the gas seal thereby negatively effecting the surgical procedure.
In order to maintain the integrity of the gas seal at the incision and to support the cannula in a hands-off manner, it has been known to provide various mechanisms and devices such as external sleeves which attempt to maintain and secure the cannula in the incision. However, many of these devices serve one function only, such as preventing unintentional removal of the cannula from the incision, or other functions such as limiting penetration of the cannula into the body cavity to prevent damage to tissues if the cannula is over-inserted.
Typical devices include penetration limiting devices such as the sleeve or collar disclosed in U.S. Pat. No. 3,817,251 to Hasson, which provides a conical sleeve which may be adjusted to various positions on the cannula to limit insertion of the cannula to specific depths. The sleeve positioned on the cannula provides some form of gas sealing, but only if the cannula is maintained in its fully inserted position, so that the sleeve is fitted into the incision. However, such a device provides no means for preventing the backing off of the cannula as the integrity of the gas seal may be compromised due to the movement of the cannula during the surgical procedure.
U.S. Pat. No. 4,077,412 to Moossun, as well as U.S. Pat. No. 4,627,838 to Cross et al., disclose devices to prevent the inadvertent removal or backing off of the cannula during the surgical procedure. Moossun provides an inflatable diaphragm member which is inflated once the cannula is positioned in the body cavity. The balloon type diaphragm prevents inadvertent removal of the cannula from the incision until the diaphragm is deflated. Cross et al. provide a complex wing-type mechanism which is extended once the catheter is positioned within the body cavity so that the wing members engage the body wall to prevent removal of the catheter until the wing mechanism is collapsed.
Also known in the prior art are sleeve members having external ribs, where the sleeve fits over the cannula and is forced into the incision either by twisting or simply by forcing the sleeve into the incision along with the catheter. Such devices may damage the surrounding tissue if improperly inserted, and if the sleeve is too large for the incision, may lead to tearing of the tissue.
The novel tissue gripping device for use with a cannula of the present invention obviates the disadvantages encountered in the prior art and provides a simple device for attaching to the cannula to hold the cannula in place during the surgical procedure to prevent inadvertent removal or over-insertion of the cannula into the body cavity. Alternately, the device may be constructed integrally with the cannula. The device of the present invention allows a surgical team to avoid having to hold the cannulas during a surgical operation, to free the surgical team to handle the implements necessary to effect the surgical objective. The device of the present invention also provides the required gas sealing necessary to perform laparoscopic surgical procedures.